1. Field of the Invention
The present invention relates to a laser projector to display an image by scanning light projected from a laser light source on a projection surface.
2. Description of Related Art
As a laser projector using laser as a light source, there is known an art for displaying an image by projecting a laser beam to a screen from a laser light source and scanning the laser beam in two-axis directions by a reflection using a resonance mirror, for example.
The laser beam projected to the screen from the laser projector is scanned with an irradiation angle being changed by the mirror. Accordingly, a trapezoidal distortion, i.e., a phenomenon where an image projected on the screen becomes larger as a distance from the projector to the screen becomes longer, may arise.
As an art for correcting the trapezoidal distortion, there is generally known an art for correcting an image so that the image becomes a rectangle by performing image processing in a projector.
Further, there is known a laser projector wherein an image to be projected on a screen is corrected and displayed by measuring a distance from the projector to the screen and adjusting the angle at which a mirror scans a laser beam according to the measured distance. (For example, refer to JP-A-2008-268645.)
However, in the conventional art mentioned above, there has been a problem that information can be partly missing by optical image processing and that an image quality of the displayed image can be degraded.
Moreover, in the case of JP-A-2008-268645 mentioned above, the laser beam reflected on the screen may not return toward the projector because the irradiation angle of the laser beam to the screen is shallow etc., for example. In that case, the processing for correcting the image can not be performed when the reflected light can not be detected at a light receiving section and the distance from the projector to the screen can not be measured.
Furthermore, when the mirror increases or decreases a scan width by adjusting the angle at which the mirror scans the laser beam in order to correct the trapezoidal distortion, there has been a need for adjusting the angle properly so as not to increase the scan width too much or decrease it too much.